Method and apparatus for manufacture of staple fiber

ABSTRACT

Staple fibre from viscose is obtained by a continuous operation wherein filaments from a large number of spinning nozzles are combined to form a thick bundle and led vertically upwards and downwards a number of times over a series of rolls or similar deviating members, the thick bundle while travelling upwards being freed from tension, washed and, if desired, desulphurized, bleached, and again washed, the treatment liquid flowing in counter current, and the bundle is then passed to drying devices such as heated rollers, and to cutting devices.  The filament bundle may be treated with dilute ammonia or soda solution during the first washing process so as to neutralize acids.  In order to free the bundle from tension during the liquid treatment, the rollers may be rotated at different speeds or brake rods or plates may be provided.  The filament bundle may be cut to staple fibre while still containing a considerable amount of moisture.  The bundle may be curled by passing it while damp between grooved drying plates or rods arranged in the form of a grid.  The plates may be heated electrically, by gas flames, or by heated air.  They may be on endless bands and moved in the direction of the filaments.  As shown in Fig. 2, a large number of filaments 5 are combined together by rollers 17 and guides 18 to form a thick bundle 21 which passes up and down between rollers 22-37.  The upper rollers are driven at a lower peripheral speed than the lower rollers so that the filaments are free from tension during the upward run, and under tension when moving downwards.  Washing liquid is applied to the upwardly moving filaments from spraying nozzles 24, 38, 39, 40.  Dilute soda solution is applied from the nozzles 41, and water from nozzle 42.  The filament bundle passes to a drying drum 44 and then &lt;PICT:0443076/IV/1&gt; &lt;PICT:0443076/IV/2&gt; &lt;PICT:0443076/IV/3&gt; cutting device 51.  As shown in Fig. 3, the curling device consists of drying plates 53, 54 with interengaged grooves.  As shown in Fig. between grooved drying plates 49, 50 travelling on endless bands in the direction of the bundle.  The curled filament bundle then reaches a 4, closely arranged rods in grid form between which the bundle passes in a sinuous path are used as the curling device.

E. WITTE April 9, 1940.

7 METHOD AND APPARATUS FOR MANUFACTURE OF STAPLE FIBER Filed Aug. 7, 19:55

Patented Apr. 9, 1940 UNITED/STATES PATENI OFFICE] i t I 2,196,449 7 I AND APPARATUS FOR MANUFAC- TUBE F STAPLE FIBER. Erhard Witte, Berlin-Lichterfelde, Germany, as- 1 signor to North American Rayon Corporation,

Y 'MErnoD New York, N. Y., a corporation of Delaware Application August 7,1935, Serial No. 35,161

g In Germany August 14, 1934' I The present. invention relates to the manufactureof artificial silkfilaments from cellulosic spinning solutions, but primarily has for its object the production of staple fiber'ina continu- 1 5 ous. operation.

It has heretofore been the practice in the art to produce staple fiber from artificial silk .byfirsttwisting a large number of freshly spun threads into a rope-like hank and then winding 7 10 it upon reels'in order to be subjected to the usual immediately .upon the spinning thereof, and. then subjecting them.-to the usual after-treat-- ment. j It has also been proposed to stop interzo mitt'ently' the extrusion of the threads through the spinnerettes in order to produce short pieces of thread. The after-treatment of these short 1 pieces of thread, however, require many manipulations which increase the cost of production. Still another method of producing staple fiber which has been proposed is the spinning of threads into spinning pots; The latter are r0- tated at high speed, wherebythe moisture is extruded from the :yarn. This process has also proved very costly due to the amount of labor required to obtain the. finished product. I In a copending application, Serial Number 28,679, to Erhard Witte', filed June 27, 1935, a process is disclosed forsimplifying and improving' the manufacture of staple fiber from filaments of cellulosic origin in continuous opera-' tion-thus overcoming the disadvantages of the methods. heretofore" used and outlined above. This process comprises the steps of collecting the into one large bundle of threads and leading the said bundle upand down a plurality of times over a series of guiding devices, whereby, during the upward passage thereof and when no'tenis washed andafter-treated in counter-current stream of treating solution.

i It is a purpose'of the present invention to improve the washing of thejthread bundle in the 5 0 process of the above mentioned] application.

In the further development of this process it I was found possible to improve the washing of the thread bundle while moving upwardly, if water of at least 46 C, was used. This temthreads from a large number of spinning places sion is imparted thereto,'the bundle of threads perature was particularly suitable because it 00- incided with the boiling point temperature of carbon bisulphide, so thatthe carbon bisulphide remaining in the freshly spun thread was easily removed therefrom. Simultaneously with the removal of the carbon bisulphide other gases contained therein were released and thus removed from the thread bundle. 1 r

The waste gases arising therefrom in; large quantities, which gases have always proved greatly detrimental to the quality of artificial place where and disposed of.. g

The present invention provides a tube or incasement for surrounding the thread bundle and which is connected toasuction device. The

device is so constructed that the thread bundle" can freely'enter and leave through top and bottom openings. It is advisable to construct the tube in such a manner that it may .be'opened longitudinally in order to reach the thread bundle if necessary. The tube is preferably provided with inspection openings or the entire device may be made from glass in order to enable the operator to watch the washing process. An exhauster or some similar device is positioned at the upper end of the tube for carrying off *the deleterious gases which are present'in a rather concentrated form. Due tothe degree of concentration they may be easily. condensed or otherwise rendered harmless by any well known manner.

The present applicationtherefore relates to 4 erenceindicate like parts, I- indicates the thread bundle which is ledaround a guide roller 2 rotating at a higher circumferential speedthan the guiding device 3. The thread bundle I enters the tube-like jacket through the lower opening 4 and after passage through the said ,tube 5 passes out of the opening 6 to'the guide roller 3. A nozzle 'l is placed above the thread.

- I and directs a washing spray thereon. The

treating solution used. preferably has a temperayarn, are removed from thethread bundle at a they may most easily be carried off ture of 46 C. and washes the thread by passing counter-currently thereto.

A suction or exauster device 9 is connected at 8 to the jacket 5 for the purpose of carrying off the waste gases therefrom.

It is, of course, understood that the temperature-of the washing solution may be of a higher temperature than 46 C. in order to speed up the removalof the carbon bisulphide and the other gases contained in the thread.

From the foregoing specification, taken in con.-

nection with the accompanying drawing, it is thought that complete operation, construction and the advantages of the novel process and apparatus will be clear to those skilled in the art to which it relates.

counter-current water bath maintained at at least 46 (3., and simultaneously drawing off deleterious gases therefrom.

3. A device for use in the continuous wet-treatment of filaments of artificial origin comprising,

an upper and a lower rotatable thread guiding means, a tube disposedbetween said thread guiding means and positioned to surround thread passing between. said guiding means, a suction device attached to said tube inclose proximity to its upper end, and spraying means positioned above said upper thread guiding means.

4. A device of the type set forth comprising, a vertically disposed, tubular chamber, rotatable means positioned to pass thread vertically through said chamber, a suction device'attached to the upper portion of the chamber, and. a spraying means positioned above the upper end of said chamber. '1

5. A device for use in the continuous wet-treatment of filaments of artificial origin comprising, a vertically disposed tubehaving a bottom and a top. opening of reduced diameter, a duct in said tube in close proximity to the top opening, a suction device attached to said duct, rotatable thread guiding means positioned to pass thread vertically and upwardly through said tube, and spraying means above said top opening adapted to spray the thread counter-currently to its direction of travel. r

6. In a method of Wet-treating strands of freshly spun viscose filaments, the step of simultaneously' drawing off gases released from said strands while theyare being washed by a countercurrent. bath during their travel vertically upward in an un-tensioned condition.

7. In the manufacture of artificial yarn by the viscose process, the step which includes passing the yarn without subjecting it to tension through a tubular chamber, washing the. yarn in said chamber with a counter-current bath, and simultaneously subjecting theyarn to suction to remove deleterious gases therefrom. 8/In a method of wet-treating strands of freshly spun filaments of artificial origin, the step of washing the filaments while in an untensioned condition in a counter-current flow .of liquid and at the same time acting upon the filaments with suction so as to remove gases released during such liquid treatment.

' ERH'ARD 

